Olympus Mons
Olympus Mons is the tallest known volcano and mountain in our solar system, located on the planet Mars at approximately 18° N 133° W. Olympus Mons is located in the Tharsis bulge, a huge swelling in the Martian surface that bears numerous other large volcanic features. Among them are a chain of lesser shield volcanoes including Arsia Mons, Pavonis Mons and Ascraeus Mons, which are small only in comparison to Olympus Mons itself. Olympus Mons is a shield volcano, which means that it is the result of highly fluid lava flowing out of volcanic vents over a long period of time, and is much wider than it is tall; the average slope of Olympus Mons' flanks is very gradual. In 2004 the Mars Pathfinder orbiter imaged old lava flows on the flanks of Olympus Mons. Based on crater size and frequency counts, the surface of this western scarp has been dated from 115 million years in age down to a region that is only 2 million years old. This is very recent in geological terms, suggesting that the mountain may yet have some ongoing volcanic activity. The central edifice of Olympus Mons stands 17 miles (27 Km) high above the planet's surface level (about three times the elevation of Mount Everest above sea level). It is 342 miles (550 Km) in width, flanked by steep cliffs, and has a caldera complex that is 53 miles (85 Km) long, 37 miles (60 Km) wide, and up to 1.8 miles (3 Km) deep with six overlapping pit craters. Its outer edge is defined by an escarpment up to 4 miles (6 Km) tall; unique among the shield volcanoes of Mars. The Hawaiian Islands are examples of similar shield volcanoes on a smaller scale (see Mauna Kea). The extraordinary size of Olympus Mons is likely due to the fact that Mars does not have tectonic plates. Thus, the crust remained fixed over a hot spot and the volcano continued to discharge lava, bringing it to such a height. A person standing on the surface of Mars would be unable to view the upper profile of the volcano even from a distance as the curvature of the planet as the volcano itself would obscure it. However, one could view parts of Olympus Mons'';' standing on the highest point of its summit, the slope of the volcano would extend beyond the horizon, a mere 1.8 miles (3 Km) away; from the 1.8 miles (3 Km) elevated caldera rim one could see 50 miles (80 Km) to the caldera's other side; from the southeast scarp highpoint (about 3 miles (5 Km) elevation) one could look about 112 miles (180 Km) southeast; from the northwest scarp highpoint (about 5 miles (8 Km ) elevation) one could look upslope possibly 149 miles (240 Km) and look northeast possibly 143 miles (230 Km). The caldera at the peak of the volcano was formed after volcanism ceased and the roof of the emptied magma chamber collapsed. During the collapse the surface became extended and formed fractures. Later additional caldera collapses were formed due to subsequent lava production. These overlapped the original circular caldera, giving the edge a less symmetrical appearance. Two of the craters on '''Olympus Mons have been provisionally assigned names. These are the 9.6 mile (15.6 Km) diameter Karzok crater (18°25′N, 131°55′W) and the 6.4 mile (10.4 Km) diameter Pangboche crater (17°10′N, 133°35′W). The land immediately surrounding Olympus Mons is a depression in the bulge 1.2 miles (2 Km) deep. The name Olympus Mons devires from the Latin, "Mount Olympus". Olympus Mons viewed on Google Mars Category:Volcanoes